Brief Summary

Introduction

Lycoteuthids are mostly small, muscular squids occupying mesopelagic depths during the day and migrating into near-surface waters at night. They are tropical and subtropical in distribution but are not known from the North Pacific. They possess a large variety of luminous organs. Oval photophores are found on the tentacles, eyeballs and viscera in all species and on the arms, head, mantle and fins in some. Strong sexual dimorphism in general morphology occurs in some species.